I've taken a large step towards Olympus, at least in the wildlife and hiking area of Photography, I'm still on the fence with low light though. I've started to sell the Sony lenses that I used primarily for wildlife and/or hiking:
Sony 70-200mm - the replacement is the Olympus 40-150mm
Sigma 150-600mm - but already replaced!
Sony 55mm - I decided to sell this one as I rarely used it
Sony 35mm - Also rarely used
Samyang 14mm - I had already replaced this one with the Zeiss Batis 18mm, so it wasn't used
The ones that I'm keeping for now:
Zeiss Batis 18mm, f/2.8
Sony 16-35mm, f/4
Sony 24-70mm, f/4
Sony 90mm f/2.8 macro
These are my most used lenses, other than telephoto. I'll see how the tests go with the Olympus in low light, but they'll be staying for now.
So what's the big step? What have I done?
From the list of lenses that I am selling, you may have already figured it out. I've bought the M.ZUIKO DIGITAL ED 300mm 1:4.0 IS PRO. When used with the 1.4x teleconverter it increases the reach to 420mm. This is the equivalent in full-frame of 600mm, respectively 840mm. All this and weatherproof too.
I'd narrowed down the choice to two lenses, the Olympus 300mm and the Panasonic 100-400mm. I was initially leaning towards the Panasonic because of the versatility of the 100-400 range, and honestly, the price is also more appealing. I decided to take a look at the images that I'd taken with the Sigma 150-600 (the lens that this replaces) to see which focal ranges I had used. I saw that most of them were shot at the far end, so either 600mm or 840mm with the 1.4x teleconverter. These numbers correspond to the focal lengths of the Olympus 300mm (with the 35mm equivalence). So even though there is versatility in the zoom range, it's something that I apparently don't use much.
The decision then moved towards the 300mm. It's a prime, the image quality is better, the autofocus speed is great, I don't have to think about the zoom, and it's weatherproof.
I'm really looking forward to getting back up into the Vosges to look for the Chamois.